Innovative Simulation Approach to Analyze and Add Value to Upcoming Complex Drive Cycle (WLTC) for Passenger Cars

Vehicles which are sold and put into service in a country have to meet the regulations and standards of that country. Every country has a separate regulation and approval procedure which requires expensive design modifications, additional tests and duplicating approvals. Thus, there is the need to harmonize the different national technical requirements for vehicles and form a unique international regulation. With this rationale, the World Forum for Harmonization of Vehicle Regulations of the United Nations Economic Commission for Europe (UN/ECE/WP29) has brought governments and automobile manufacturers together to work on a new harmonized test cycle and procedure which is to be adopted around the world. This lead to the development of Worldwide Harmonized Light Duty Test Procedures (WLTP) and Cycles (WLTC). The test procedure is divided into 3 cycles, depending on a power to mass ratio of the tested vehicle. Test cycles in WLTP are developed with an aim to represent typical driving conditions around the world. This was further shared across various participating nations for evaluation and their recommendations on the same.

Evaluating new procedures and test cycles is a time consuming affair and is prone to errors if evaluated by physical testing. Moreover it is tedious and impractical to evaluate drivability and fuel economy of numerous vehicles on WLTC using chassis dyno. In order to overcome above mentioned shortcomings, methodology to use Simulation Tools was devised for the evaluation. This paper provides an overview on how Software Tools such as Matlab/Simulink and AVL Cruise have been effectively used to analyze different vehicles on WLTC. Results of these analyses highlighted characteristics of proposed test cycle and its impact on vehicle drivability and fuel consumption of vehicle.

Based on these analyses necessary recommendations were provided during various stages of WLTC development.